Pipe joint and method of constructing the same



March 5, 1935. H. w. FLETCHER 1,993,269

' PIPE JOINT AND METHOD OF CONSTRUCTING THE SAME Filed March 9, 19:51

HAROLD WFLETcHs/P INVENTOR ATTORNEY Patented 5, 1935 PATENT OFFICE PIPE JOINT ANIl mrmon OF coNs'raUcr- ING THE sum:

Harold W. Fletcher, Houston, Tom, anignor to Hughes Tool Company, Houston, Ten, a

poration 0! Texas Application March 9, 1931, Serial No. 521,103

laims.

My invention relates to joints for pipes but has particular application to tool joints ior use on drill stem'employed in well drilling by the rotary method.

Drill stem must be oi. strong and durable con= struction, due to the fact that it is subjected to high twisting torque in rotating the drill, and the sections 01' the drill stem must be unscrewed and again connected when the drill is withdrawn from the hole. It

has become customary in ham diing drill stem to screw tool joints on the meet ing ends of the drill stem sections, said joints serving to withstand the wear of repeated screw= ing up and unscrewing when the drill stem. is handled in These tool joints include a pin member and a box member, each of which 1 has athreaded socket at one end for connection with the ends of the pipe sections. These sockets are subjected to heavy torsional strains in drill ing and are flexed to some extent in the drilling operation, so that eventually they are liable to leakage and wear by the erosion or the flushing mud. Many tool joints iailbecause of this wear and have to be replaced.

-.It is an object of my invention to provide a construction oi. tool joint, whereby the tool joint may become in effect an integral part 0! thepipe, and all danger from leakage and wear between the joint and the Pin practically eliminated.

- The invention includes the method by means of which the tool joint is constructed and at tached to the pipe joint.

I aim to do away with the threaded connection between the pipe, and provide joint members and the drill a strong and sturdy construction which will withstand the heavy duty to which it is subjected.

I also aim to do this in a simple and economical manner,-which willbe a practiizable manulecturing operation,

,In the drawing herewith, Fig. 1 is a central longitudinal section through a tool joint embodying my invention.

Fig. 2 is' a section through the broken lower end 0! a pipe section with the reinforcing collar thereon.

Fig. 3 is a broken section oi-the upper end of memberi.

'Ihetoolioint areemployedale endsiacedoflmendSotthetooljoint oitheradn member 5 ora box member 6, both of which are threaded for connection at 'l in the usual manner. The outer diameter of the joint members is larger than is that oi the pipe, thus providingv a shoulder at 3 which projects outside the area 5 with which the pipe contacts.

Outside the pipe, at each end I employ a reinforcing collar 8 which fits the pipe closely and has its end faces oi! squarely with the pipe to fit against the shoulder 3 on the joint member. its outer periphery is then flush with the outer periphery of the tool joint,

- The pipe and collar are then welded to the tool'joint by any prei'errcd manner. I content plate, for example, the welding of the pipe and collar to the tool joint by electric welding in which the meeting ends are subjected to the heat of the are and then forced tightly together and allowed to cool somewhat, and then I sub- 29 ject the union to iiu'ther heating i'rom the eiec= trio current to obtain the proper steel structure oi the joints and then allow the weld to cool. in this way", I obtain a jinn union of the pipe and collar to the joint and a heat treatment oi the material thereafter. It is to be understoodhcw ever, that other welding processes may be used.

When thus welded, the connection appears op proxiinately as shown in 1, the pipe and col iar being, in eiIect, integral parts oi the tool joint. 30 The joint is not removable from the pipe, except by cutting with a torch or otherwise, and will not be subject, to wear and leakage due to flush ing fluid as is now the case with'threaded connections.

It'will be seen that this joint is a simple and economical construction and will eliminate many 01 the objectionable features experienced with tool joints in recent years.

m reinforcing collar has the eiiect of reducing stress concentration, due to the flexing of the pipe. This is important, as it is iound that breakage oi the pipe with threaded joints almost invariably occurs in the last engaged thread at the coupling. This is true even where the pipe 45 is upset for greater strength at the ends. In my joints, there are no threads, and the reinforcing collar prevents flexing of the pipe at the weld, and a strong durable joint results. Such a joint has no leaks, no expense for upsetting oi the pipe is necessary. It eliminates threading of the pipe,

the joint is as strongas the-pipe itself.

'whatlclaimasnewisz m 1. Adeviceoithecharacterdescribedincluding tubular drill stem sections, a tool joint including a tapered threaded pin member and a box memher having a tapered threaded socket to receive said pin member, each of said tool joint members having its ends remote from said pin and socket formed with a plane shoulder, collars fitted over the ends of each of said drill stem sections and both said sections and said collars secured integrally with a pin member at one end of said section and a. box member at the other end thereof.

2. A tubular drill stem section, collars fitting over the ends of said section, a taper threaded pin member at one end of said section, a box member at the other end of said section, said box having a threaded socket tapered to receive a tapered pin member, said collars and said section being welded integrally with the ends of said pin and box members in the manner described.

3. A tool joint and drill stem combined including a tubular pin member with one end tapered and threaded, the other end having a plane shoulder, a box member with a tapered threaded socket to receive said pin and a plane shoulder at its outer end and a collar about the ends of said pipe section, said collars and the ends of sections being secured integrally to said shoulders on said members, one end to a pin member and the other end to a box member.

4. A method of connecting together tubular drill stem sections comprising fitting a reinforcing metal collar about the ends of the section, forming a, tapered threaded tool joint member and then butt-welding the ends of said drill stem section and collar to the ends of said tool joint members remote from their taper threaded ends, 5. A method of making an integral drill tube coupling including forming a tool joint member with tapered inner surfaces, forming tapered threads on the interfitting ends of the joint members, outwardly reinforcing the ends of the said drill tube sections by metal collars, and then butt-welding said drill pipe section and said collars to the ends of said tool joint members remote from their threaded ends.

6. The method of making an integral drill stem coupling, comprising forming a tool joint member with tapered box and pin cooperating ends thereon, forming threads on the interfitting ends of said tapered box and pin, outwardly reinforcing the end of the drill stem section by a. metal collar and then butt-welding said drill pipe. section and collar to said tool joint member, and then heat treating the welded portion.

HAROLD W. FLETCHER. 

